Method for manufacturing silicon carbide single crystal

Abstract

Provided is a method for manufacturing a silicon carbide single crystal capable of easily separating a silicon carbide single crystal from a pedestal. The method includes the step of fixing a seed substrate to a pedestal with a stress buffer layer being interposed therebetween, the step of growing a silicon carbide single crystal on the seed substrate, the step of separating the silicon carbide single crystal from the pedestal at the stress buffer layer, and the step of removing a residue of the stress buffer layer adhering to the silicon carbide single crystal subjected to the step of separating.

The invention claimed is: 
     
       1. A method for manufacturing a silicon carbide single crystal, comprising the steps of:
 fixing a seed substrate to a pedestal with a stress buffer layer being interposed therebetween; 
 growing a silicon carbide single crystal on the seed substrate; 
 separating the silicon carbide single crystal from the pedestal at the stress buffer layer; 
 removing a residue of the stress buffer layer adhering to the silicon carbide single crystal subjected to the step of separating; and 
 the step of fixing the seed substrate includes a step of bonding the stress buffer layer and the pedestal with a first adhesive layer and a step of bonding the stress buffer layer and the seed substrate with a second adhesive layer. 
 
     
     
       2. The method for manufacturing the silicon carbide single crystal according to  claim 1 , wherein, in the step of separating, the silicon carbide single crystal is separated from the pedestal at the stress buffer layer by pressing a wire extending in a direction along a main surface of the stress buffer layer, from an end surface of the stress buffer layer into the stress buffer layer. 
     
     
       3. The method for manufacturing the silicon carbide single crystal according to  claim 1 , wherein, in the step of separating, the silicon carbide single crystal is separated from the pedestal at the stress buffer layer by emitting a laser beam to the stress buffer layer. 
     
     
       4. The method for manufacturing the silicon carbide single crystal according to  claim 1 , wherein, in the step of removing the residue, the residue of the stress buffer layer is removed by heating the silicon carbide single crystal under an oxygen-containing atmosphere. 
     
     
       5. The method for manufacturing the silicon carbide single crystal according to  claim 4 , further comprising the step of heating the silicon carbide single crystal under an inert gas atmosphere,
 wherein the step of heating is continuously performed after the step of removing the residue. 
 
     
     
       6. The method for manufacturing the silicon carbide single crystal according to  claim 2 , wherein, in the step of removing the residue, the residue of the stress buffer layer is removed by heating the silicon carbide single crystal under an oxygen-containing atmosphere. 
     
     
       7. The method for manufacturing the silicon carbide single crystal according to  claim 3 , wherein, in the step of removing the residue, the residue of the stress buffer layer is removed by heating the silicon carbide single crystal under an oxygen-containing atmosphere. 
     
     
       8. The method for manufacturing the silicon carbide single crystal according to  claim 6 , further comprising the step of heating the silicon carbide single crystal under an inert gas atmosphere,
 wherein the step of heating is continuously performed after the step of removing the residue. 
 
     
     
       9. The method for manufacturing the silicon carbide single crystal according to  claim 7 , further comprising the step of heating the silicon carbide single crystal under an inert gas atmosphere,
 wherein the step of heating is continuously performed after the step of removing the residue. 
 
     
     
       10. The method for manufacturing the silicon carbide single crystal according to  claim 1 , wherein the stress buffer layer is made of a material which is less hard than the seed substrate. 
     
     
       11. The method for manufacturing the silicon carbide single crystal according to  claim 1 , wherein the stress buffer layer includes a graphite sheet.